1. Field of Invention
The present invention relates to fiber optic sensors, and in particular, to a system using fiber optic sensors to measure vibration in downhole electric submersible pump systems.
2. Description of Related Art
Electrical submersible pump (ESP) systems may be deployed within a wellbore to pump downhole fluid to the surface. An ESP system may typically include an electric motor and a pump that is used to pump oil or other fluids within a wellbore. The electric motors have a rotatable rotor that is contained within a stationary stator. During operation in a wellbore, ESP systems may vibrate for multiple reasons. For example, when fluid film bearings are used to protect between a rotor shaft and a bearing sleeve, the bearings may become destabilized due to lack of an applied side load to cause excessive motor vibration. Motor vibration induces the bearings to vibrate, that in turn can cause the bearing sleeve to break through the oil film. When the oil film is breached, metal to metal contact occurs that can lead to premature wear and motor failure. Motor vibration can also occur when unexpectedly high levels of gas are being pumped by the ESP. While vibration monitoring systems may be employed, vibration measurements are typically limited to average overall levels.